AC Not Cooling? What to Check Before You Call in Berks County

An AC not cooling on a hot night is usually one of five things you can check yourself: the thermostat on Cool with the fan on Auto, the filter, the breaker and the outdoor power switch, ice on the copper line, and water under the indoor unit. None of them needs a tool.

If none of them brings the cold back, you'll call one of the HVAC companies in Berks County knowing what to say and roughly what it costs. First, though, look at who's in the house.

Anyone over 65, an infant or young child, anyone pregnant, or anyone with a chronic condition shouldn't wait out a hot night, so get them somewhere cool now. Someone who's confused, with hot dry skin, or who passes out has heat stroke, and that's a 911 call.

For anyone over 60, the Berks County Area Agency on Aging answers 610-478-6500 weekdays 8 to 5, with 24-hour emergency service, and for everyone 211 is Pennsylvania's free referral line around the clock. If the bill is the worry, there's help paying for heating and cooling.

What to check before you call anyone.

Work these in order. None of them involves taking a panel off anything.

1. The thermostat. Make sure it says Cool, with the set number below the room number. Auto runs the fan only while the system is cooling; the On setting runs it all the time, so between cycles the vents push room-temperature air that feels like a failure. Set the fan to Auto, and try fresh batteries if the screen is blank.

2. The filter. Pull it out and look at it. If it's gray and packed with dust, it's choking the airflow, and a system that can't move air can't cool it and can freeze itself solid. Put in a new one, and check it monthly from now on.

3. The breaker and the outdoor switch. A tripped breaker can rest close to On, so push the AC breaker fully to Off and back to On, then make sure the power switch near the outdoor unit is on. If it trips again after one reset, stop. A breaker that keeps tripping is a job for a licensed electrician.

4. Ice on the copper line. Look at the copper line running into the outdoor unit. Ice on it means the system has frozen up, and running it that way can do major damage. Switch the thermostat from Cool to Off and the fan to On, and leave it alone for now.

5. Water under the indoor unit. The indoor unit is the furnace or the cabinet beside it. A puddle there means the drain for the water the system pulls from the air is clogged, and some systems shut themselves off when that happens. Put a towel down. It's usually the drain.

If one of those brought the cold back, you're done for tonight. If not, keep going.

Why does my air conditioner freeze up?

Why does an air conditioner freeze in August? Because it blows warm indoor air across a cold coil in the indoor unit, and refrigerant, the chemical that carries heat from that coil out to the outdoor unit, runs through it.

Starve it of warm air and it gets colder than it should, and the moisture in the air freezes onto it.

Too little air is one of two things you can fix: a clogged filter, or a return vent, the big grille that pulls room air back into the system, with a couch or a rug over it. The third cause is low refrigerant, and refrigerant only gets low when there's a leak.

The fix tonight is to let it thaw. Switch the thermostat from Cool to Off and the fan to On, so warm air melts the ice, and expect one to four hours depending on how much built up. Don't chip at it, because the coil is easy to damage, and put a towel under the indoor unit.

Then change the filter, uncover every return vent, and turn it back to Cool. If it freezes again after that, call, because a second freeze with a clean filter and open vents points to low refrigerant or something mechanical.

Why is my air conditioner leaking water?

Where does the water come from? An air conditioner pulls a lot of it out of humid Berks air, and it drips off the coil into a pan and out through a drain line. When that line clogs, the pan overflows onto the floor, and a plugged drain can damage the house.

A float switch is a sensor near the pan that shuts the system down when the water rises too high. Not every system has one, but if yours does and it tripped, that's why the AC went quiet. The switch isn't the fault. It's the system refusing to make more water it can't drain.

Turn the system off, mop up, and tell the dispatcher there's water and whether it shut itself off, and clearing the line is part of the visit. If you also found ice on the copper line, the water is probably the thaw, not the drain.

What you shouldn't touch, and why.

Start with refrigerant. The system is a closed loop, so it doesn't use up refrigerant the way a car uses gas, so if it's low, it's leaking, and the fix is to repair the leak and then recharge, in that order.

Under federal rules only a certified technician can buy refrigerant for a home system or work on its lines, so a low charge is a call, not a project.

Inside the outdoor unit is a capacitor, a part that stores a high-voltage charge, and it can hold enough of that charge to injure or kill you after the breaker is off. So the panels stay on. Clearing leaves from around the outside is fine, and opening it isn't.

Wiring is the last one. Anything behind a panel is licensed work, and a breaker that trips a second time is the system telling you so.

What to tell the dispatcher when you call.

Start with the HVAC companies in Berks County page and pick one near you. Berks Plumbing & HVAC Specialist in Reading is on it, and a company that does plumbing as well as HVAC is a fit when the problem is water on the floor.

Having answers ready saves time on the phone and the visit. If anyone from the risk groups above is in the house, say so in your first sentence, along with how hot it is inside.

Then say what you've got: an outdoor unit with an indoor unit on the furnace, which is the common setup, or everything in one cabinet outside, and roughly how old it is. Then what it's doing: not turning on, running but warm, running cold but not keeping up, shut itself off, water on the floor, ice on the line.

Then what you checked: thermostat on Cool and Auto, filter changed or not, breaker reset once or tripped twice, and whether the outdoor unit is running or silent. A breaker that tripped twice turns the call from a cooling problem into an electrical one, and they'll want to know before they send anyone.

Finish with access: where the units are, a locked gate, a dog, and the brand on the outdoor unit if you can read it.

What the call costs in Berks County.

Here's what three companies in our HVAC listings charge for the visit itself, as of 2026.

Company	Published visit fee
MDT Heating and Air Conditioning, Honey Brook (Chester County, near the Berks line)	$119 for an AC diagnostic visit.
Clark's Heating & Cooling, Reading	$145 for a 90-minute cooling repair visit, and $150 for heating.
Kodiak Comfort Heating and Air Conditioning, Wyomissing	$0 dispatch fee for Care Club members, who never pay a trip charge.

So what does the visit cost? It's its own line on the bill: nationally a diagnostic runs $75 to $250, and an after-hours add-on is $50 to $200 or more on top.

Ultimate Comfort Heating & Cooling in Wernersville offers extended service hours with no overtime fee, and some companies drop the trip charge for plan members, so ask what tonight costs before the truck rolls.

Kodiak Comfort Heating and Air Conditioning in Wyomissing puts a $0 dispatch fee in writing for its Care Club members, and it's worth asking any company whether a plan gets you the same.

What HVAC contractors charge per hour in Berks County covers the labor once the technician is in. If the estimate makes you wince, read the $5,000 rule for repair or replace and what a new AC costs in Berks County before you say yes.

Frequently asked questions.

Why is my AC running but not blowing cold air?

Check the fan setting first. On instead of Auto makes the fan blow room-temperature air between cooling cycles, which feels like a failure and isn't. If it's on Auto and the air is still warm, go down the list above.

Can I add refrigerant to my AC myself?

No. Only a certified technician can buy it for a home system, and a low system has a leak anyway, so refrigerant added on top of a leak doesn't stay. The small cans at the auto parts store are for cars only.

And if it's the furnace that won't start instead, the furnace version of this post runs the same way: the safe checks, then the call.

Sources

• Carrier, "Why Is My AC Blowing Hot Air?" (read September 5, 2026) and Honeywell Home, "How can I change the fan operation setting" (read September 5, 2026): set to Cool with the fan on Auto; confirm the breaker and the outdoor unit's power switch; tell the technician what you already checked.
• U.S. Department of Energy, "Energy Saver 101: Everything You Need to Know About Home Cooling" (read September 5, 2026): thermostat and battery checks, a clogged filter's effect on cooling, a clogged drain, repairing the leak and then recharging, clearing leaves and debris from a split system, and the split versus packaged definitions.
• ENERGY STAR, "Maintenance Checklist" (read September 5, 2026): check the filter once a month; a plugged condensate drain can cause water damage in the house.
• Carrier, "Will Frozen AC Fix Itself?" (read September 5, 2026): thaw procedure, one to four hours to unfreeze, and a repeat freeze meaning low refrigerant, restricted airflow or a mechanical problem.
• Trane, "What To Do If the AC Evaporator Coil Is Frozen" (read September 5, 2026): ice on the coil or the lines, puddles as it thaws, switching from Cool to Off, not chipping the ice, the damage from running it frozen, and blocked return vents and low refrigerant as causes.
• Trane, "Troubleshooting the HVAC Air Handler Overflow Switch" (read September 5, 2026): the float switch shuts the system down when water rises, a clogged line or pan is the usual cause, and not every system has one.
• Electrical Safety Foundation International, "Indoor Electrical Safety Check" booklet (read September 5, 2026): a tripped breaker can rest near On, so move it fully to Off and back; breakers that trip often call for a licensed electrician.
• U.S. EPA, "Section 608 Technician Certification Requirements" (read September 5, 2026) and U.S. EPA, "Refrigerant Sales Restriction" (read September 5, 2026): who must be certified, that putting gauges on the lines is a technician's act, that only certified technicians may buy refrigerant for home equipment, and that the small-can exception is for cars.
• Carrier, "What is a Home AC Recharge?" (read September 5, 2026): the closed loop doesn't consume refrigerant, so low means a leak.
• Carrier, "AC Capacitor" (read September 5, 2026): capacitors store high-voltage electricity that can cause serious injury or death even when the power is disconnected.
• CDC, "People at Increased Risk for Heat-Related Illness" (read September 5, 2026): people 65 and older, infants and young children, pregnancy, and chronic medical conditions as higher-risk groups.
• Berks County, "Area Agency on Aging" (read September 5, 2026): 610-478-6500, Monday through Friday 8:00 am to 5:00 pm, 24 hour emergency service.
• Fixr, "AC Repair Cost: Common Issues & When to Replace" (read September 5, 2026): national diagnostic fees of $75 to $250 and after-hours, weekend and holiday surcharges of $50 to $200 or more.
• MDT Heating and Air Conditioning, services page (read September 4, 2026): "AC DIAGNOSTICS $119 Report included."
• Clark's Heating & Cooling, online booking page (read September 4, 2026): "Cooling Repair 1 hr 30 min $145" and "Heating Repair 1 hr 30 min $150."
• Kodiak Comfort Heating and Air Conditioning, Care Club page (read September 4, 2026): "$0 Dispatch Fee. Members never pay a trip charge."
• Ultimate Comfort Heating & Cooling, company site (read September 4, 2026): "We offer extended service hours with no overtime fee."
• Electrical Safety Foundation International, "Air Conditioner and Fan Safety" (read September 5, 2026): a qualified, licensed electrician for any electrical work on cooling equipment.
• Ready PA, "Extreme Heat" (read September 5, 2026): heat stroke signs (confusion, hot dry skin, unconsciousness) and the instruction to call 911 immediately.
• PA 211 (read September 5, 2026): dial 211, free, available around the clock every day.